Ultra-Low Latency Remote Application Access

ABSTRACT

An ultra-low latency remote access system may stream video images from a remote application server to a client device, but may render a cursor separately on the client device. The remote application may send cursor bitmaps and other cursor information to the client device, which may be rendered by the client device to give a near-native response time and feel to the user experience. The remote access system may operate in a browser environment, with executable code in the browser to capture user input, including pointer and keyboard inputs. Executable code on the application server may encode screen images into video, which may be transmitted and rendered on the client device. In some cases, the rendered video may be larger than the displayable area of the client device, allowing for panning and zooming to be performed on the client device.

BACKGROUND

Remote access to computer systems has been around since the originalmainframe computers. The classic access method is to have dedicatedhardware, such as a remote terminal, or specialized software that wouldrun on a remote device. The software for the remote device wouldcommunicate with a server and allow bi-directional communication.

For a typical remote access system to work, the remote device would haveto download and install a native client application. The native clientapplication would capture operating system-level input, such as mouselocation and keyboard inputs, and transmit the information to theapplication server. The application server would treat the inputs fromthe client application as if the user were interacting with theapplication server directly.

In most use cases, a remote application access system has a problem oflatency, which may be perceived as responsiveness by the end user. Inany remote access situation, there will be additional latencies fromnetwork connection issues.

SUMMARY

An ultra-low latency remote access system may stream video images from aremote application server to a client device, but may render a cursorseparately on the client device. The remote application may send cursorbitmaps and other cursor information to the client device, which may berendered by the client device to give a near-native response time andfeel to the user experience. The remote access system may operate in abrowser environment, with executable code in the browser to capture userinput, including pointer and keyboard inputs. Executable code on theapplication server may encode screen images into video, which may betransmitted and rendered on the client device. In some cases, therendered video may be larger than the displayable area of the clientdevice, allowing for panning and zooming to be performed on the clientdevice.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings,

FIG. 1 is a diagram illustration of an embodiment showing browsercontrol of a remote computer.

FIG. 2 is a diagram illustration of an embodiment showing a networkenvironment with browser control of a remote computer.

FIG. 3 is a flowchart illustration of an embodiment showing a method forsetting up a communications session.

FIG. 4 is a flowchart illustration of an embodiment showing a method formanaging cursors.

FIG. 5 is a diagram illustration of an embodiment showing an oversizedvideo transmission for zoom/pan support.

FIG. 6 is a flowchart illustration of an embodiment showing a method forselecting and adjusting a rendered area.

DETAILED DESCRIPTION Ultra-Low Latency Remote Application Access

An ultra-low latency remote access system may stream video images from aremote application server to a client device, but may render a cursorseparately on the client device. The remote application may send cursorbitmaps and other cursor information to the client device, which may berendered by the client device to give a near-native response time andfeel to the user experience.

The remote access system may give a user the experience of operating aremote application with an experience similar to having the applicationoperating natively on the client device. By having a remote accesssystem, a powerful remote application server may be able to process andrender complex applications that would not be possible or practical toimplement on a client device.

For example, a remote application server may be executing a 3D ComputerAided Design (CAD) program, which may be accessed and controlled by atablet computer. The remote application server may have much moreprocessing and rendering capability than the tablet computer, yet theuser may interact with the 3D CAD program as if the program were runningnatively.

By rendering cursor movements on the client device, the user experiencesimulates a native application. This is because the cursor movementcomes from the operating system of the client device, where theresponsiveness is the same as a native application.

Compare such a system to one where cursor location information may becaptured on the client device, sent to the remote server, rendered onthe remote server, then the rendering transferred to the client device.In such a system, the responsiveness of the cursor may be severelylimited by the round-trip travel time to the remote server and back.

Rendering the cursor natively may eliminate the round-trip lag time orlatency, which can give a user a much more comfortable experience, evenif the remote application image updates still have the lag time of theround-trip.

The remote access system may generate a video stream on the remoteapplication server and transmit the video stream to a browser on theclient device. The remote application server may render images that maybe captured by a remote application service. The service may generate avideo stream that may be sent to the client device.

A video stream may be useful to send rendered images, as several videocompression technologies can be used to compress and transmit the videostream. However, video streaming technologies are generally designedwith inherent buffering technologies, any of which may add to latency.Some video compression technologies may be tuned to minimize bufferingor other causes of latency.

For example, many video compression technologies may rely on differencesbetween two or more images to eliminate the similar areas of the images.Such technologies inherently buffer multiple frames to achieve thecompression goals, but in doing so introduce latency for each of thebuffered frames. In a conventional video streaming situation, suchlatency may be immaterial, but in a real-time or near-real time systemwhere a user may be attempting to control a remote application through agraphical user interface, such latency may be detrimental.

In many cases, video streaming may be assisted by using hardware orsoftware codecs on the remote application server and, in some cases, onthe client device. Such codecs may operate without taking much, if any,processing cycles from either a central processing unit (CPU) orgraphical processing unit (GPU). In some cases, a hardware codec may notbe available and a CPU or GPU may be employed for encoding or decoding avideo stream.

The remote access system may operate in a browser environment, withexecutable code in the browser to capture user input, including pointerand keyboard inputs. The browser executable code may be JavaScript codethat may be downloaded in a Hyper Text Markup Language (HTML) document.

By embedding the client-side executable code in an HTML document, anybrowser can be used on any device to execute any application on a remoteaccess server. This can be done without creating, supporting, anddownloading native applications that would be specific to each hardwareand software platform. The client-side browser-executable code may makedeploying the remote access system much easier than when using aclient-side native application.

The rendered image on the remote application server may be sized tomatch the displayable area of a client's browser. In some cases, therendered image may be a pixel-to-pixel match to the client device, whilein other cases, the rendered image may be larger or smaller than thedisplayable area of the client's browser.

A pixel-to-pixel relationship between the rendered image on a remoteapplication server and a displayable area of a client's browser may beuseful in situations to maximize the resolution of the image. Forexample, an application that may contain small text may remain readableand useful with a pixel-to-pixel relationship.

A non-pixel-to-pixel relationship between the rendered image on a remoteapplication server and the displayed image on a client device may beuseful in several situations.

For example, a lower resolution rendered image may generate a videoimage that may be smaller than what may be rendered on a client device.Such systems may upscale the displayed video to match the viewable spaceon a client device. Such a configuration may be useful in low bandwidthsituations as well as when the resolution of the image may not be ofhigh importance. For example, a real-time action game may be rendered ina lower resolution than may be displayed as a lower resolution of therendered image may not take away from game play.

In another example, a higher resolution rendered image may generate avideo image that may be larger than what may be rendered on a clientdevice. Such an example may be useful when the client device may becapable of panning the video while viewing, or when the client devicemay downscale the video image prior to viewing.

The browser-based control of a remote computer may enable a multi-usersystem, where one user may operate a remote computer while other userspassively view the video provided from the remote computer. In somecases, two or more users may be able to control cursor movement and makecursor-related inputs to the remote computer. In some such cases, two ormore users may collaborate by operating the same application on theremote device. Many such systems may have a shared audio channel, whichmay be delivered along with the video stream, or may be a separatechannel. Some such systems may connect users through the telephonesystem for audio while the video and cursor controls may be providedthrough a digital data network connection.

Throughout this specification, like reference numbers signify the sameelements throughout the description of the figures.

When elements are referred to as being “connected” or “coupled,” theelements can be directly connected or coupled together or one or moreintervening elements may also be present. In contrast, when elements arereferred to as being “directly connected” or “directly coupled,” thereare no intervening elements present.

In the specification and claims, references to “a processor” includemultiple processors. In some cases, a process that may be performed by“a processor” may be actually performed by multiple processors on thesame device or on different devices. For the purposes of thisspecification and claims, any reference to “a processor” shall includemultiple processors, which may be on the same device or differentdevices, unless expressly specified otherwise.

The subject matter may be embodied as devices, systems, methods, and/orcomputer program products. Accordingly, some or all of the subjectmatter may be embodied in hardware and/or in software (includingfirmware, resident software, micro-code, state machines, gate arrays,etc.) Furthermore, the subject matter may take the form of a computerprogram product on a computer-usable or computer-readable storage mediumhaving computer-usable or computer-readable program code embodied in themedium for use by or in connection with an instruction execution system.In the context of this document, a computer-usable or computer-readablemedium may be any medium that can contain, store, communicate,propagate, or transport the program for use by or in connection with theinstruction execution system, apparatus, or device.

The computer-usable or computer-readable medium may be, for example butnot limited to, an electronic, magnetic, optical, electromagnetic,infrared, or semiconductor system, apparatus, device, or propagationmedium. By way of example, and not limitation, computer readable mediamay comprise computer storage media and communication media.

Computer storage media includes volatile and nonvolatile, removable andnon-removable media implemented in any method or technology for storageof information such as computer readable instructions, data structures,program modules or other data. Computer storage media includes, but isnot limited to, RAM, ROM, EEPROM, flash memory or other memorytechnology, CD-ROM, digital versatile disks (DVD) or other opticalstorage, magnetic cassettes, magnetic tape, magnetic disk storage orother magnetic storage devices, or any other medium which can be used tostore the desired information and which can accessed by an instructionexecution system. Note that the computer-usable or computer-readablemedium could be paper or another suitable medium upon which the programis printed, as the program can be electronically captured, via, forinstance, optical scanning of the paper or other medium, then compiled,interpreted, of otherwise processed in a suitable manner, if necessary,and then stored in a computer memory.

When the subject matter is embodied in the general context ofcomputer-executable instructions, the embodiment may comprise programmodules, executed by one or more systems, computers, or other devices.Generally, program modules include routines, programs, objects,components, data structures, etc. that perform particular tasks orimplement particular abstract data types. Typically, the functionalityof the program modules may be combined or distributed as desired invarious embodiments.

FIG. 1 is a diagram illustration of an embodiment 100 showing an examplesystem where a browser may be used to interactively control a remotecomputer. In the example, a server 102 may be controlled by a client104, where an operating system desktop 108 and application window 110may be rendered on the server, and the browser 112 may display at leasta portion of the operating system desktop 108. The browser may captureand transmit keyboard, mouse, and other inputs to the server 102, whichmay send the inputs to the application on the server 102.

The renderings from the display of the server 102 may be captured by animage capture component 114 and encoded with a video codec 116 to createa video stream. The video stream may be passed across a network 118 tothe client 104, which may receive the video stream, decode the videostream with a video codec 120, and display the video stream using avideo player 112 onto the browser window.

“Real time” or “near-real time” control of an application on a server102 by another device, in this case client 104, may introduce variouscomplexities. Ideally, the user may make an input, such as a mouseclick, keyboard input, or other input, and the user would experienceinstantaneous response. The fact that the two devices communicate witheach other introduces latencies, as well as the availability of limitedor variable network connections.

Video compression and transmission techniques are widely used, and anyappropriate format, compression algorithms, codecs, and other protocolsmay be used. Video capture and compression mechanisms may be lossy,where some of the information may be lost during the compressionroutine, while other mechanisms may not be lossy.

Some of the video compression and transmission techniques may introducelatency into the system. Many video compression techniques may use datafrom one or more frames to compress information in later frames. Suchtechniques may inherently capture two, three, or more frames, performcompression using the frames, then transmit the video. One mechanism toreduce latencies may be to select a video compression and encodingtechnique that uses a minimum of frames during the compression process.Some video compression and encoding mechanisms may have configurationsettings that may permit adjusting the encoding techniques.

Video compression mechanisms that have been successfully implementedwith such a system include H262, H263, H264, and others.

A second mechanism by which user-perceived latency may be reduced may beto have cursor movement and rendering performed on the user's localdevice, rather than on a remote device. From the user's standpoint, themotion and feel of a cursor and its responsiveness to movement may givea perceived “real time” feel, even when the cursor inputs have a latencywhen they are transmitted and processed on a remote system.

Local rendering of the cursor can cause the cursor to move with the sameresponsiveness within a browser window as with any other application ona client device. For cursors that may be controlled with mice or otherpointing device, such a responsiveness may give an acceptableexperience, and in some cases, users may not realize that the operationsperformed within a browser window may actually be performed and renderedon a remote device.

Embodiment 100 may illustrate a system where cursor information is notincluded in the video transmitted from the server 102, and where thecursor information may be rendered by the client 104.

In some systems, a cursor manager 126 may be capable of removing anyrendered cursor from an image captured by the image capture component114. Some such systems may capture a bitmap of the rendered screen,identify the cursor location, and change the bitmap to remove thecursor.

In other systems, the operating system of the server 102 may beconfigured so that the cursor may be very small or not rendered, whichmay obviate the step of removing a cursor from the rendered image.

A cursor manager 126 may identify the specific cursor being used by theapplication or operating system of the server at a specific instance.The cursor manager 126 may transmit an image of the cursor in a bitmapor other form to the client 104. The client 104 may have a cursormanager 132 which may cause the cursor image to be rendered locally onthe client 104.

Some applications may have multiple cursors that may change based on thecontext of the cursor, a tool that may be selected, or some otherfeature of the application. For example, an image editing system mayhave a cursor in the shape of an eyedropper for sampling colors, abracket cursor used for editing text, a crosshair cursor for selecting arectangular box, and so forth. Each time the cursor may be changed, thecursor manager 126 may identify the cursor and relay the cursorinformation over the server signaling channel 124 to the client 104.

In some cases, the cursor manager 126 may send an identifier for aspecific cursor, and the client 104 may use one of several storedcursors 134 that corresponds to the identifier. Such systems maytransmit an image of a cursor the first time that cursor may beencountered, then each time thereafter, may merely send the identifierinstead of the image. The client 104 may have a cursor manager 132 thatmay cause the local cursor to change to a different cursor in responseto a change in the cursor identifier.

A controller 136 on the server 102 may use a server signaling channel124 and a client signaling channel 144 to communicate with the client104 during setup, tear down, and normal operations. The client 104 mayhave a server signaling channel 130 and a client signaling channel 140connected to a client controller 138.

The signaling channels may be illustrated here as separatecommunications channels. In some cases, the channels may be separatesockets, ports, protocols, or be otherwise separate from the channelthrough which video may be transferred. In other cases, some or all ofthe server signaling channel communications may be embedded or encodedinto the video stream, thereby having a single port, channel, protocol,socket, or other channel from the server 102 to the client 104.

The client 104 to server 102 communications may be a separate channel,port, protocol, socket, or other mechanism than from the serversignaling channel. In some cases, the client signaling channel may be aduplex version of the server signaling channel, where both directions ofcommunication may use the same port, channel, protocol, socket, or othercommon mechanism.

The client 104 may have a mechanism to capture mouse, keyboard, andother input 142. These inputs may be captured and transmitted throughthe client signaling channel 140 to the server 102. The server 102 mayreceive the data through the client signaling channel, and may providethe input to the operating system 146. These inputs may be passed to theapplication executing within the operating system and thereby the userof the browser 112 may operate an application on the server 102.

The inputs collected on the client 104 may include any type of input,including keyboard, mouse, audio, as well as sensory input fromgyroscopes, global positioning system (GPS) sensors, accelerometers,temperature sensors, pressure sensors, light sensors, and any other typeof sensor that may be available on the client 104. In some cases, theinputs may include camera input that may be collected from a cameramounted on the client 104 or connected to the client 104. The camera maybe able to capture still images or video, and such inputs may betransmitted over the client signaling channel 140. In the case of videoor audio inputs, such inputs may be encoded using a codec andtransmitted to the server 102 for decoding prior to use.

The example of embodiment 100 may illustrate a system where a browser112 may render the contents of an application window 110. This exampleis merely one use case, such as where the server 102 may be configuredjust to provide a specific application through the browser 112. Othersystems may display multiple applications and even the entire operatingsystem desktop 108 in the browser 112. Such applications may allow forthe entire server 102 to be controlled by the client 104 through thebrowser 112.

FIG. 2 is a diagram of an embodiment 200 showing components that may beused for remote access of an application or system through a browser.

The diagram of FIG. 2 illustrates functional components of a system. Insome cases, the component may be a hardware component, a softwarecomponent, or a combination of hardware and software. Some of thecomponents may be application level software, while other components maybe execution environment level components. In some cases, the connectionof one component to another may be a close connection where two or morecomponents are operating on a single hardware platform. In other cases,the connections may be made over network connections spanning longdistances. Each embodiment may use different hardware, software, andinterconnection architectures to achieve the functions described.

Embodiment 200 illustrates a device 202 that may have a hardwareplatform 204 and various software components. The device 202 asillustrated represents a conventional computing device, although otherembodiments may have different configurations, architectures, orcomponents.

In many embodiments, the device 202 may be a server computer. In someembodiments, the device 202 may still also be a desktop computer, laptopcomputer, netbook computer, tablet or slate computer, wireless handset,cellular telephone, game console or any other type of computing device.In some embodiments, the device 202 may be implemented on a cluster ofcomputing devices, which may be a group of physical or virtual machines.

The hardware platform 204 may include a processor 208, random accessmemory 210, and nonvolatile storage 212. The hardware platform 204 mayalso include a user interface 214 and network interface 216.

The random access memory 210 may be storage that contains data objectsand executable code that can be quickly accessed by the processors 208.In many embodiments, the random access memory 210 may have a high-speedbus connecting the memory 210 to the processors 208.

The nonvolatile storage 212 may be storage that persists after thedevice 202 is shut down. The nonvolatile storage 212 may be any type ofstorage device, including hard disk, solid state memory devices,magnetic tape, optical storage, or other type of storage. Thenonvolatile storage 212 may be read only or read/write capable. In someembodiments, the nonvolatile storage 212 may be cloud based, networkstorage, or other storage that may be accessed over a networkconnection.

The user interface 214 may be any type of hardware capable of displayingoutput and receiving input from a user. In many cases, the outputdisplay may be a graphical display monitor, although output devices mayinclude lights and other visual output, audio output, kinetic actuatoroutput, as well as other output devices. Conventional input devices mayinclude keyboards and pointing devices such as a mouse, stylus,trackball, or other pointing device. Other input devices may includevarious sensors, including biometric input devices, audio and videoinput devices, and other sensors.

The network interface 216 may be any type of connection to anothercomputer. In many embodiments, the network interface 216 may be a wiredEthernet connection. Other embodiments may include wired or wirelessconnections over various communication protocols.

The software components 206 may include an operating system 218 on whichvarious software components and services may operate.

Various applications 220 may execute within the operating systemenvironment. Some or all of the applications 220 may be made availablefor remote control through a client device 252 and a browser 258.

The operating system 218 may have a rendering engine 222 which mayrender displayable images based on input from the operating system 218and various applications 220. The rendering engine 222 may be anoperating system function that may use a graphics processing unit 224,which may be a hardware or software accelerator that may assist inrendering graphics.

The server 202 may have a server side executable 226, which may be a setof software components that may permit external control of the entiresystem or a subset of the system through a client device 252. The serverside executable 226 is illustrated as a set of software components as amatter of convenience, but some or all of the components may beimplemented in hardware.

An image capture component 228 may capture the rendered images from therendering engine 222. The image capture component 228 may be anoperating system function in some systems or may be a separate componentthat may intercept rendered images that may be displayed on a monitor.

A cursor remover component 230 may be used in systems that may render acursor within the displayable image. Some systems may not have a cursorremover component 230 and may include the rendered cursor in the videostream. In such a case, the client device 252 may or may not have aseparately rendered cursor.

When the video stream includes a rendered cursor and when the clientdevice also has a separately rendered cursor, a user may experience twocursors on the screen. The cursor rendered on the server 202 andembedded in the video stream may not be as responsive as the cursorrendered by the client 104, however, in most cases, the client-renderedcursor may overlap or hide the server-rendered cursor. A user mayexperience that the server-rendered cursor may slightly lag behind themovement of the client-rendered cursor.

A server 202 may render a cursor and the client device 252 may beconfigured not to render a cursor over the browser 258. In such a case,the user interaction with the browser 258 may generate a location wherea cursor may be at any given time, and the location may be transmittedto the server 202, then rendered in the video stream viewed on theclient device 252. Such systems may have some latency or lag that may beexperienced by the user of the client device 252. In cases where thenetwork and video processing latencies are not exceptionally high, theuser experience may still be acceptable.

A server 202 may be configured to not render a cursor at all in theimage generated by the rendering engine. In such cases, the renderedimage may not have a cursor, so the only cursor a user of the client 252may experience may be the cursor rendered by the client 252.

An image sequence from the image capture component 228 may be sent to avideo codec 236 and then communicated to the client device 252 by acommunications manager 238.

The communications manager 238 may handle a server signaling channel240, which may send control information and other information to theclient device 252.

The server signaling channel 240 may be used to send cursor informationto the client device 252. The cursor information may include thelocation of a cursor as well as the type of cursor being displayed. Thecursor type may be an identifier for a specific cursor. The serversignaling channel 240 may also be used to send a bitmap or other imageof a cursor for rendering on the client device 252. In some cases, theclient device 252 may request a cursor image when a specified cursor maynot be available on the client device 252, and the cursor manager 232may be able to send the requested cursor from a group of stored cursors234.

A controller 242 may manage various administrative functions for theclient/server interaction. The administrative functions may includesetup and teardown of a session, monitoring and adjustment ofcommunications settings, and other functions. The controller 242 of theserver 202 may operate in conjunction with controller 272 of the client,and in some cases, either controller 242 or 272 may initiate or respondto one of the various administrative functions.

During setup and teardown of a communications sessions, some use casesmay have controllers 242 or 272 provide authentication and configurationof a session. In some scenarios, a client device 252 may request aconnection from the server 202 or may be routed to a server 202 aftermaking a request to a third device, such as a connection managementsystem 280.

When a connection request is received, the controller 242 may set up theapplications 220 prior to establishing a video stream. In some cases, anew instance of an application may be established and, when the instancebecomes stable, a video stream may be created. In some such cases, asingle server 202 may provide separate video connections to multipledevices, each device having a separate session with different instancesof an application or with multiple devices sharing the same instance orsession with a single instance of an application.

A setup operation may involve starting a new instance of an applicationand configuring the application based on parameters or data that may beprovided with a request for a new session. For example, an applicationmay be configured to resume operations from a previously saved session,or may be started with a set of options requested by a user.

Teardown of a session may involve terminating an application instance orreconfiguring the server 202 in some manner in preparation for a newsession. In some cases, the server 202 may maintain its configurationand various application instances in case the session termination wasinadvertent. In other cases, the server 202 may terminate one or moreapplications and free up resources for new sessions that may berequested at a later time.

The controllers 242 and 272 may monitor and adjust communicationssettings due to network or other performance issues. For example, thecontrollers may identify a change in the network bandwidth, and may beable to adjust the video or other communications to take advantage ofadditional bandwidth or reduce transmissions to accommodate lessbandwidth. The video communications may be adjusted by changing thevideo frame rate, density or compression of pixels within the images, orother parameter changes. The specific changes may depend on the specificvideo compression and encoding algorithm.

The controllers 242 and 272 may be able to monitor and displayconnection quality and responsiveness to an end user, such as displayinga red/yellow/green light or bar graph for connection strength. When aconnection problem may be recognized, the controllers may be able topresent a dialog box, warning, notice, or other message on the user'sscreen on the browser 258.

The client signaling channel 246 may handle inbound communications fromthe client device 202. One element of inbound communications may bekeyboard/mouse input 278 as well as other input captured by the clientdevice's browser 258. These inputs may be communicated from thecommunications manager 264 on the client device 252 to thecommunications manager 238 on the server 202 and the client signalingchannel 246. These inputs may be transferred as inputs to the operatingsystem 248.

The keyboard/mouse input 278 may include any type of input captured bythe client device 252. These inputs may include audio, video, GlobalPositioning System (GPS), accelerometer input, orientation sensors,temperature and pressure sensors, and any other type of input that maybe captured by the client device 252. In some cases, the input may bedata gathered by or presented by applications executing on the clientdevice 252 or accessed through the network 250 to some other device. Forthe sake of convenience, the term keyboard/mouse input 278 includes allof the various inputs listed above.

The client device 252 may have a hardware platform 254 on which anoperating system 256 may operate. The hardware platform 254 may includeany of the various options and characteristics described for thehardware platform 204. A browser 258 may execute on the operating system256.

The browser may have a display window 260, as well as an executableengine 262. The executable engine 262 may be a virtual machine,emulator, interpreter, compiler, or any other mechanism by whichinstructions may be executed. In today's browser technologies, manybrowsers include a Javascript engine that may execute Javascript thatmay be contained in an HTML document that a browser 258 may render.

Incoming video data may be decoded by a video codec 266 and shown on thebrowser's display window 260 by a video player 268. In many cases, avideo player 268 may include controls for starting, stopping, rewinding,fast forwarding, or other functions. In some cases when the browser maybe used to control a remote device, such as the server 202, suchcontrols may be turned off or otherwise unavailable to the user.

A client side executable 270 may contain code that may be executed onthe browser's executable engine 262. The client side executable 270 maybe downloaded as part of an HTML page, and in some instances, thecomponents of the client side executable 270 may be embedded inJavascript or some other executable language.

The client side executable 270 may include a controller 272, acommunications manager 264, a cursor manager 274, and stored cursors276. The client side executable 270 may include routines or othercomponents that may capture keyboard/mouse inputs 278.

The cursor manager 274 may determine which cursor is to be shown at aparticular time. The cursor manager 274 may receive a bitmap or otherimage of a cursor and store the image in a set of stored cursors 276. Inmany cases, the cursor manager 274 may receive an identifier which mayidentify the current cursor. The identifier may be any type ofidentifier, such as a set of numbers, letter, hashed values, or otheridentifier. The cursor manager 274 may look up the corresponding cursorimage from the stored cursors 276, and may pass the cursor image to thebrowser 258 for rendering.

In some cases, a certain cursor may be applicable to a specific area ofa rendered application, while a second cursor may be applicable to adifferent area of the rendered application. In such cases, the cursormanager 274 may receive a map or boundary area identifying a specificcursor to use while other areas of a displayed video image may have adifferent cursor. Some applications may have several cursor images thatmay apply to different areas or zones of a rendered video image.

The network 250 may be any type of network that may allow the server202, client device 252, and other devices to communicate.

A connection management system 280 may be a device that may help set upsessions between client devices and servers. The connection managementsystem 280 may operate on a hardware platform 282 with an operatingsystem 284. A connection manager 286 may receive an inbound request froma client device 252 for a session. The connection manager 286 may use anauthentication service 288 to determine whether or not the requestor mayhave permission to establish a session. Provided that the authenticationis successful, a load balancer 290 may select between multiple instancesof a server 202 to direct the client to establish a session.

In some cases, the connection manager 286 may setup and configure anapplication 220 on a server 202 specifically for an inbound request,then give the address of a server 202 for establishing a connection.

Some servers 202 may be configured so that multiple client devices mayconnect to a single session. In some such cases, one or more clientdevices may be configured to provide input to an application executingon the server 202, while other client devices may be configured tomerely monitor, watch, or view the display window without providingcontrol to the window. In some cases, control of an application on aserver 202 may be changed from one device to another.

A monitoring client 292 may have a hardware platform 294 on which anoperating system 296 may operate. A browser 298 may connect to thecommunications manager 238 and may render a display window 299, whichmay be the same image as rendered on the browser 258 of the clientdevice 252. In some cases, certain inputs may be received from themonitoring client 292, such as audio, keyboard, mouse, or other inputs,and may be transmitted to the server 202. Such inputs may be transmittedas inputs to the operation system 248, although in other instances, someof the inputs generated by monitoring client 292 may be transmitted tothe client device 252 for rendering and display within the browser 258.

FIG. 3 is a flowchart illustration of an embodiment 300 showing a methodof setting up a communications session. Embodiment 300 is a simplifiedexample of a sequence showing a load balancer 302 in the left handcolumn, a server 304 in the center column, and a client 306 in the righthand column.

Other embodiments may use different sequencing, additional or fewersteps, and different nomenclature or terminology to accomplish similarfunctions. In some embodiments, various operations or set of operationsmay be performed in parallel with other operations, either in asynchronous or asynchronous manner. The steps selected here were chosento illustrate some principals of operations in a simplified form.

Embodiment 300 may illustrate one method by which a new session may becreated. A load balancer 302 may provide initial setup functions,including authentication and setup, then a session may be createdbetween the server 304 and client 308 where the client 308 may controlthe server 304 or an application running on the server 304.

A client 306 may send a request for a web page in block 308 to the loadbalancer 302. The load balancer 302 may receive a request in block 310,then request authentication credentials in block 312. The authenticationrequest may be received by the client 306 in block 314, and may send thecredentials in block 316.

The load balancer 302 may receive authentication credentials in block318 and verify the credentials in block 320. In some cases, thecredentials may be passed to a separate authentication service. Afterverifying the credentials in block 320, the load balancer 302 may send aweb page with server information and authentication token in block 322to the client 306.

In some cases, the load balancer 302 may also send set up orconfiguration instructions to the server 304, while in other cases, suchconfiguration instructions may be included in the web page with serverinformation. In this example, a web page is a shorthand notation forinstructions for how to access the server 304 from the client 306. Inmany cases, such instructions may be embodied in an HTML document, whichmay include executable scripts or other instructions.

The web page may be received in block 324 by the client 306. The client306 may sent a request with the authentication token in block 326, whichmay be received by the server 304 in block 328. The server 304 mayverify the token in block 330, and may send client executable code inblock 332 to the client 306. The client 306 may receive the clientexecutable code in block 334 and may begin execution in block 336.

The server 304 may send a video stream in block 340 that may representthe operating system desktop of the server 304, an application executingon the server 304, or some other “live” image of the server 304. Thevideo stream may be received and rendered in block 338. The client 306may generate and send client data in block 346, which may includekeyboard, mouse, and other inputs, which may be received by the server304 in block 348. The keyboard, mouse, and other inputs may be used tocontrol the application or operating system running on the server 304,and thereby a user of the client 306 may operate the server 304 througha browser.

FIG. 4 is a flowchart illustration of an embodiment 400 showing a methodof handling cursors in a browser-control system of a remote server.Embodiment 400 is a simplified example of a sequence showing a server402 in the left hand column and a client 404 in the right hand column.

Other embodiments may use different sequencing, additional or fewersteps, and different nomenclature or terminology to accomplish similarfunctions. In some embodiments, various operations or set of operationsmay be performed in parallel with other operations, either in asynchronous or asynchronous manner. The steps selected here were chosento illustrate some principals of operations in a simplified form.

Embodiment 400 may illustrate a process that may be performed between aserver 402 and client 404 when the client 404 may render a cursor imagelocally, but may be providing input to and controlling the server 402 orat least an application on server 402.

An outbound video stream may be created in block 406 by the server 402and transmitted to the client 404. The client 404 may receive the videostream in block 408 and may render the video stream within a browser. Inblock 410, the client 404 may gather and send a cursor location to theserver 402, which may receive the cursor location in block 412.

The cursor location may also include interactions or commands that maybe executed with the cursor location. Such commands may be a left-click,right-click, center-click, scrolling, or other location-sensitivecommands. The cursor location may be sent to the operating system inblock 414, along with any commands or other input.

The cursor image generated by the server 402 may be intercepted in block416. In some cases, the operating system of the server 402 or anapplication executing on the server 402 may have a signaling system totransmit a cursor image that may be displayed at the location selectedby the user. Some applications may have cursor images that may reflect afunction, command, setting, or other operational characteristic of theapplication. Some applications may change cursor images based on thelocation of the cursor within the application, and such image changesmay signify different available operations to the user.

In many cases, a cursor image may have one or more transparent pixels orbits. In some cases, the transparent pixels or bits may be partiallytransparent.

The server 402 may generate a cursor identifier for the cursor image.The cursor identifier may be any shorthand notation or identifier for aparticular cursor image. One mechanism for identifying a cursor imagemay be to perform a hash function on the image and generate analpha-numeric or numeric designation. The hash function may be selectedsuch that changes to the image may result in changes to the identifier,thereby signaling that the cursor has changed.

The cursor identifier may be looked up in the cursor database in block422. If the cursor image does not exist in the cursor database in block424, the server 402 may send the cursor image and identifier in block426 to the client 404.

The client 404 may receive the cursor and identifier in block 428 andmay store the cursor and identifier in a local cursor storage in block430. The client may cause the cursor image to be used for the currentlocation of the cursor in block 432 and the process may loop back toblock 410.

If the cursor does exist in the server's cursor database in block 424,the cursor identifier may be transmitted in block 434. The client 404may receive the cursor identifier and may look up the cursor identifierin the cursor database in block 436. If the cursor identifier andcorresponding image exists locally in the cursor database in block 438,the client may use the cursor image in block 440.

If the lookup fails in block 438 and the identified cursor is notavailable locally, the client 404 may request a cursor image in block442, which may be received by the server 402 in block 444. The server402 may return to block 426 and may transmit the cursor image andidentifier.

In some cases, a cursor image may be defined for a specific regionwithin a rendered area of a video stream. For example, when a cursorhovers over a text object, the cursor may be changed to a text editingcursor, but such a cursor may be only valid for the region of a textbox. Such a map, overlay, or other description of where certain cursorsmay be valid may be generated on the server 402 and transmitted to theclient 404 in some embodiments. In some cases, the server 402 maygenerate a map of the rendered area and may define which cursors may bevalid at various locations within the map. Some such systems may have adefault cursor that may be used wherever a special cursor may not bedefined.

FIG. 5 is a diagram illustration of an example embodiment 500 showing anover-sized video transmission from a server 502 to a client 504. Theover-sized video transmission may be a higher resolution or larger sizethan may be displayed in a browser on the client 504.

Embodiment 500 may illustrate one use case of an over-sized videotransmission. An over-sized video transmission may be any configurationwhere the server 502 may transmit a video stream that may be larger thanthe displayed area on the browser of the client 504. The over-sizedvideo in this example may be useful for panning and zooming the videostream rendered on the client 504.

In such a configuration, any zooming or panning of the video stream maybe performed on the client 504, which may be faster and more responsivethan if the zoom or pan commands were transmitted to the server 502 andupdates made to the rendered video stream.

A zoom command may expand or contract the displayed area or viewportrendered in a browser on the client 504. A pan command may allow theclient 504 to move the displayed viewport horizontally or verticallywithin the rendered area of the video.

Zoom and pan commands may be issued on the client 504 by a user. In somecases, the user may have a mouse navigation mechanism, such as a specialmouse button and movement commands, or a mouse movement in conjunctionwith a keyboard command, such as a shift key, alt key, or control key.In other cases, a zoom or pan command may be issued by moving thedevice, such as through accelerometer inputs when a user may move adevice, such as a mobile device, through space.

A server 502 may generate a rendered area 506, which may be captured andencoded into video using a video encoder 508. The video stream may betransmitted over a network 510 to a client 504. The client 504 may havea video decoder 512 and may generate a rendered area 514. The renderedarea 514 may be the same size as the rendered area 506 on the server.

The client 504 may display a subset of the rendered area 514 as adisplayed viewport 516. The displayed viewport 516 may be moved aroundthe rendered area 514 by zoom and pan commands issued by a user.

The client 504 may capture keyboard, mouse, and other inputs 518, whichmay be transmitted over the network 510 to the server 502. The server502 may use the keyboard, mouse, and other inputs 520 to input to theapplication, causing the rendered image of the application or operatingsystem to be updated.

The cursor locations transmitted back and forth between the client 504and server 502 may be translated to compensate for the differencebetween the client's displayed viewport 516 and the rendered area 514.Typically, the server 502 may receive cursor locations based on anabsolute horizontal and vertical location from one of the corners of therendered area 506. However, the cursor of the client 504 may be limitedto be within the displayed viewport 516. The client 504 may translatethe cursor input captured on a browser to the rendered area dimensionsin the keyboard, mouse, or other input 518 that may be transmitted tothe server 502.

FIG. 6 is a flowchart illustration of an embodiment 600 showing a methodof negotiating and changing the rendered area of a video stream that maybe transmitted and displayed on a client. Embodiment 600 is a simplifiedexample of a sequence showing a server 602 in the left hand column and aclient 604 in the right hand column.

Other embodiments may use different sequencing, additional or fewersteps, and different nomenclature or terminology to accomplish similarfunctions. In some embodiments, various operations or set of operationsmay be performed in parallel with other operations, either in asynchronous or asynchronous manner. The steps selected here were chosento illustrate some principals of operations in a simplified form.

Embodiment 600 may illustrate one method by which the rendered area of avideo stream generated by a server 602 may be selected and changed.

A client 604 may determine the displayable area on a browser in block606. A zoom/pan allowance may be determined in block 608, which maydetermine how much extra size of the video stream may be allocated forlocally performed zoom and pan commands.

For some applications, no zoom or pan allowance may be used. Suchapplications may typically take up the entire browser area and may notzoom or pan within the browser screen. For other applications, notablyfirst person games, the zoom or pan actions may be a large part of theapplication's operation. Such applications may be allocated a large zoomor pan allowance.

The full size of a rendered area may be determined in block 610 from thezoom or pan allowance and the displayable area of the browser. In somecases, even without a zoom or pan allowance, a requested rendered areamay be larger or smaller than the viewable browser area. For example,some systems may be configured to downsample at the browser, where alarger rendered area may be transmitted and the video may be shrunk tomeet the viewable area on the browser. Such configurations may be usefulwhen the downsampling may offer increased resolution, especially withlossy video compression. In a typical downsampled configuration, therendered area may be two times the dimensions of the browser viewport.

In another example, a browser may be configured to upsample a videostream, such that the displayed area on the browser may be larger thanthe video rendered area. In such a situation, the browser may expand thevideo to fit the browser screen. Such configurations may be useful forapplications where less precise rendering may be acceptable or where thenetwork bandwidth may be limiting.

In block 612, the network bandwidth may be analyzed to determine whethera video stream of a certain size may be possible. Any adjustments to therequested rendered area may be made in block 614.

The client 604 may transmit a request in block 616, which may bereceived in block 618 by the server 602. The server 602 and client 604may negotiate the rendered area size in blocks 620 and 622,respectively. The negotiation may involve identifying certainpredetermined sizes that may be optimized on the server 602 or otherconsiderations. After negotiation, the server 602 may begin transmittinga video stream in block 624, which may be received and rendered in block626.

When the server 602 may detect that a change to the rendered area may beadvisable in block 628, the server 602 may initiate a negotiation inblock 620.

Similarly, when the client 604 may detect that a change to the renderedarea may be advisable in block 630, the process may go back to block 606to consider various factors that may be changed.

The client 604 may determine that a change to the rendered area may beadvised under several circumstances. For example, the client 604 maydetermine that a user may be exceeding the limits of the available roomwithin the rendered area for zoom or pan commands. In such a case, theclient 604 may request that the rendered area be expanded.

In another example, a client 604 may detect that network bandwidth maybe decreasing, causing the client 604 to request a smaller renderedarea. In yet another example, the user may reposition the browser on theclient 604, which may cause the browser's displayed viewport to changesize or aspect ratio. Such a change may indicate that a rendered areachange may be in order.

The foregoing description of the subject matter has been presented forpurposes of illustration and description. It is not intended to beexhaustive or to limit the subject matter to the precise form disclosed,and other modifications and variations may be possible in light of theabove teachings. The embodiment was chosen and described in order tobest explain the principles of the invention and its practicalapplication to thereby enable others skilled in the art to best utilizethe invention in various embodiments and various modifications as aresuited to the particular use contemplated. It is intended that theappended claims be construed to include other alternative embodimentsexcept insofar as limited by the prior art.

What is claimed is:
 1. An ultra-low latency server system comprising: atleast one processor; a first network connection; an ultra-low latencyremote service capable of execution on said at least one processor, saidultra-low latency remote service that: receives a rendered image of anapplication executing on said at least one processor; generates a videostream from said rendered image; transmits said video stream over saidfirst network connection to a remote browser; receives cursorinformation from said remote browser; and transmits said cursorinformation to said application.
 2. The ultra-low latency server systemof claim 1, said ultra-low latency remote service that further: receivesa connection request from said remote browser, said connection requestcomprising a displayable screen dimensions on said remote browser. 3.The ultra-low latency server system of claim 2, said ultra-low latencyremote service that further: generates said video stream to match saiddisplayable screen dimensions.
 4. The ultra-low latency server system ofclaim 2, said ultra-low latency remote service that further: causes saidrendered image to match said displayable screen dimensions.
 5. Theultra-low latency server system of claim 2, said displayable screendimensions being smaller than dimensions of said rendered image.
 6. Theultra-low latency server system of claim 5, said remote browser beingconfigured to pan said video stream.
 7. The ultra-low latency serversystem of claim 5, said remote browser being configured to zoom saidvideo stream.
 8. The ultra-low latency server system of claim 1, saidultra-low latency remote service that further: receives an updateddisplayable screen dimensions from said remote browser; and changes saidvideo stream to match said updated displayable screen dimensions. 9-44.(canceled)
 45. A method performed on at least one processor, said methodcomprising: receiving a rendered image of an application; generating avideo stream from said rendered image; transmitting said video streamover said first network connection to a remote browser; receiving cursorinformation from said remote browser; and transmitting said cursorinformation to said application.
 46. The method of claim 45, saidapplication being executed on said at least one processor.
 47. Themethod of claim 45 further comprising: receiving a connection requestfrom said remote browser, said connection request comprising adisplayable screen dimensions on said remote browser.
 48. The method ofclaim 47 further comprising: generating said video stream to match saiddisplayable screen dimensions.
 49. The method of claim 47 furthercomprising: causing said rendered image to match said displayable screendimensions. 50.-89. (canceled)
 90. A system comprising: at least oneprocessor; a connection management system executing on said at least oneprocessor, said connection management system that: receives a connectionrequest from a remote browser, said connection request being for remoteaccess to an application server through said remote browser; saidconnection request comprising a displayable screen dimensions for saidremote browser; determines a set of configuration settings for saidapplication server; causes said application server to be configured withsaid set of configuration settings; determines a set of connectionsettings for said remote browser; and transmits said set of connectionsettings to said remote browser.
 91. The system of claim 90 furthercomprising a load balancer that selects said application server from aplurality of application servers.
 92. The system of claim 90, saidconnection management system that further: authenticates said connectionrequest. 93.-102. (canceled)
 103. A method performed on at least oneprocessor, said method comprising: receiving a video stream from saidapplication server; displaying said video stream within a displayviewport of said remote browser; capturing cursor location coordinatessaid client device, said cursor location coordinates being within saiddisplay viewport; and transmitting said cursor cursor locationcoordinates to said application server.
 104. The method of claim 103further comprising: receiving a current cursor image and causing saidcurrent cursor image to be displayed within said display viewport ofsaid remote browser.
 105. The method of claim 104, said client devicehaving a current cursor location, said current cursor image beingdisplayed as a cursor at said current cursor location when said currentcursor location is within said display viewport of said remote browser.106. The method of claim 104, said client device having a local cursorimage, said local cursor image being displayed as said cursor at saidcurrent cursor location when said current cursor location is outsidesaid display viewport of said remote browser. 107.-110. (canceled)